According to the research conducted by the University of Extremadura Spain, melatonin reduces the cortisol and anxiety levels with enhanced mood and quality of life among fibromyalgia patients. As the fibromyalgia associated with mood disturbances, the analysis aimed to evaluate the effect of varying doses of Melatonin on mood status, cortisol levels, quality of life and anxiety among fibromyalgia patients.

Patients received different doses of Melatonin for ten straight days, with placebo given during the ten days either prior to or between Melatonin doses after a 10-day baseline period for the collection of data. The Numerical Pain Scale (NPS), Visual Analog Scale (VAS), the State-Trait Anxiety Test (STAI), the Fibromyalgia Impact Questionnaire (FIQ), the Short Form-36 Health Survey (SF-36) and enzyme-linked immunoassay were used to measure the pain, anxiety, mood, quality of life and urinary cortisol levels.

Melatonin at a dose of 9mg, 12mg and 15mg were linked with reduced NPS, FIQ total scores and urinary cortisol levels whereas, STAI scores improved after 12 mg of Melatonin, VAS and SF-36 after 9 mg of dose. All these findings display a significant role of Melatonin in improving the health of fibromyalgia patients.